Kidpic auteur John Hughes ("Home Alone" 1990) announced a nationwide casting call for the star of his "Dennis the Menace" (1993) in the spring of 1992: "We were looking for a good personality, some smarts, discipline and a good sense of humor. It's a big job for a little kid, but we wanted to have a real six-year-old play the part." They found their man in Mason Gamble, the adorable freckle-faced son of character actor Tim Gamble. Previously young Gamble had appeared in several TV spots and in a bit part in "Groundhog Day" (1993). Since his breakthrough, the actor has remained a constant